Conductor clamp with means for anchoring a conductor stringing assembly thereto

ABSTRACT

A conductor clamp for pivoting support on the outer end of a power line insulator and including means for anchoring a conductor stringing assembly aligned with the clamp seating channel until the conductor has been seated in the clamp.

United States Patent Lindsey 1 1 Dec. 19, 1972 [54] CONDUCTOR CLAMP WITHMEANS [56] ReferencesCited FOR ANCHORING A CONDUCTOR STRINGING ASSEMBLYTHERETO UN'TED STATES PATENTS l,630,423 5/1927 Gothberg ..l74/l69 X [72]lnvemor- 11: 222 Pasadena 3,274,654 9/1966 Becker ..24/l25 K a l [22]Filed June 23 1971 FOREIGN PATENTS OR APPLICATIONS [zlj Appl No 155 75720l,l5l l2/l958 Austria ..l7'4/4()R I Primary Examiner-Laramie E. AskinR I t d U.S. A l t D ta r e a e pp Ion a Attorney--W. D. Sellers et al.[62] Division of Ser. No. 845.960, July 30, 1969, Pat. No.

3,640,504. [57] ABSTRACT [52] U S C 248/63 24/125 K 174/169 A conductorclamp for pivoting support on the outer 51 I .t .Cl F16. 3100 A 7/00 endof a power line insulator and including means for 1 i 169 243125 E 135anchoring a conductor stringing assembly aligned with R, 24/135 K;248/63; 254/l34.3 R. 134.3 PA

the clamp seating channel until the conductor has been seated in theclamp.

5 Claims, 7 Drawing Figures PA'TEN-TEI] DEC 19 I972 sum 2 or 1 INVENTOR4. 6. 4/A/056V PATENTEDnEc 19 1922 SHEET 3 BF 4 III INVENT OR w y w m wr N r a A a PATENTEU I97? 3, 706, 436

sum u 4 INVENTOR u/vp CONDUCTOR CLAMP WITH MEANS FOR ANCHORINGACONDUCTOR STRINGING ASSEMBLY THERETO This application is a division ofmy copending application for United States Letters Patent Ser. No.845,960, filed July 30, 1969 now US. Pat. No. 3,640,504.

This invention relates to power line conductor stringing facilities andmore particularly to an improved method and apparatus designed to bemounted temporarily on the outer end of the insulator while supportingthe conductor free of but ready to gravitate into the seating channel ofa clamping unit.

The installation of long heavy power conductors to the free ends ofinsulators supported by power line poles, towersor the like presentsmany problems for which there have been numerous proposals. Resort hasbeen had to many expedients for pulling the conductor lengthwise of thepower line while supporting it close to the free end of the insulator.Thereafter the heavy and properly tensioned conductor must betransferred into the clamping means and secured in place. This can beanarduous and hazardous task using stringing equipment and procedurespreviously proposed.

To avoid the risks and the numerous disadvantages characterizingprevious stringing operations there is provided by this invention asimple stringing block assembly and a companion conductor clamping unitdesigned to be supported in superimposed relationship directly on theouter end of a power line insulator. The clamping unit is secured to theinsulator in conventional manner and a stringing block assembly is contoured to interlock with structural features of the conductor clampingunit with the conductor stringing passage of the block located above andin general alignment with the seating channel in the clamping unit. Theconductor is then pulled along the power line through thesimilarly-equipped insulator at each pole or tower following which theconductor supporting rollers extending crosswise of the opposite ends ofthe stringing units are released allowing the conductor to drop into theseating channel. The release of simple latch means then frees thestringing block for removal after which the conductor clamping jaw istightened against th conductor.

The stringing block is designed to hold the conductor in alignment withthe clamp seating channel despite curves in the power line andirrespective of the direction or degree of curvature. To this end thestringing block is provided with a pair of heavy duty lateral restraintrollers at its opposite ends, the rollers additionally cooperating tohold the conductor straight throughout the length of the seating channelto facilitate transfer of the conductor into the channel. In theinterests of minimum weight and cost, these roller guides are restrictedto one side of the stringing block which is designed to be supported onthe insulator with the guide rollers on that side of the line towardwhich the conductor curves.

Accordingly it is a primary object of this invention to provide aconductor clamp for use in securing a power line conductor to aninsulator and designed for interlocking assembly to a conductorstringing unit while the conductor is being pulled into place along apower line.

Another object of the invention is the provision of an improvedconductor clamp having means integral therewith for holding a conductorstringing unit properly aligned with the conductor seat in the clampuntil the conductor is transfered into the clamp seat.

Another object of the invention is the provision of a conductor clampingunit securable to the outer end of an insulator and designed tointerlock with a suitably designed cooperating stringing block assembly.

These and other more specific objects will appear upon reading thefollowing specificationv and claims and upon considering in connectiontherewith the attached drawing to which they relate.

' Referring now to the drawing in which a preferred embodiment of theinvention is illustrated:

- FIG. 1 is a top plan view of a preferred embodiment of the inventionstringingblock assembly attached to an open conductor clamping unit; 7FIG. 2 is a side elevational view on an enlarged scale taken from thelower side of FIG. 1 and showing portions broken away;

FIGS. 3, 4 and 5 are fragmentary cross-sectional views taken along lines3-3, 4-4 and 5-5 on FIG. 2;

FIG. 6 is a transverse vertical sectional view through the conductorclamping unit at its mid-length and showing the clamping jaw inassembled position; and

FIG. 7 is an exploded view in perspective of the cable clamping unit perse.

The invention conductor stringing block assembly, designated generally10, is designed for usein stringing a single power conductor while theassembly is supported directly on the outer end of the insulator towhich the conductor is to be secured. Assembly 10 is particularlysuitable for use with rigidly supported insulators of either the uprightor horizontal type, a fragmentary view of the outer free end 11 of thelatter type being generally indicated in dot-and-dash lines in FIG. 3.If of the horizontal type, there is fixed to the outer end of insulator11 a U-shaped bracket 12 well known to workers in this field. The innercap end of such bracket is provided with an integral trunnion-like stud13 aligned with the similarly-sized end 14 of a cap screw 15 mounted inthe outer leg of bracket 12.

Pivotally supported between stud 13 and cap screw 14 is a conductorclamping unit, designated generally 16. This clamping unit has certainnovel features but is otherwise generally similar to conductor clampingunits well known in the power line art. If insulator 11 is of theupright type, then the bight portion of bracket 12 extends crosswise ofthe upper end of the insulator with the bracket legs projecting upwardlyfrom the rim portions of the mounting cap so as to support the clampingunit 16 crosswise of the insulator end.

An understanding of the unique features of clamping unit 16 willfacilitate an understanding of the stringing block assembly. It will beunderstood that one lateral sidewall of conductor seating channel 17 isprovided with a pair of horizontally projecting legs 18,18 there beingone lug at either end of unit 16 each provided with a vertical opening19. Each of these holes seats the lower end 38 of a shaft 36 fixed toand projecting downwardly from the main frame 26 of the stringing blockassembly 10, as will be described in greater detail presently. Anotherspecial feature of clamping unit 16 is best shown in FIG. 2 andcomprises an integral lug or The conductor clamping unit 16 is pivotallysupported transversely of its mid-length on trunnions carried by theinsulator end cap bracket 12, these trunnions comprising thestud 13 andthe end 14 of cap screw 15. These trunnions extend into wells 13d (FIGS.3,7) and 14a (FIG. 3) respectively opening outwardly from the outer endsof bosses 13b and 14b (FIG. 7) cast integral with and projectinglaterally from the opposite sides of the main body of the clamping unit.The latch detent 20 referred to above is cast integral with and projectslaterally from oneside of boss 14b. As clearly appears from FIGS. 3, 4and 6, the conductor seating channel 17 is, of U-shape in cross sectionand has a depth substantially greater than the radius of the conductor32 to be clamped therein. The generally upright upper portions of itssidewalls, and particularly the sidewall 17a, safeguards against thepossibility of the tension in theconductor acting to pull or roll theconpower line which pullouts might otherwise occur. This likelihood isespecially apt to occur where the curvein the line coincides with a risein the terrain to one or both sides of the. clamping unit. The depth ofchannel 17 will therefore be understood as providing an important marginof safety for workmen required to be present while transferring aconductor into channel 17 and while assembling and tightening clampingjaw 63.

Stringing block assembly has a mainframe'26 formed by two castings26a,26b secured together at their opposite ends by bolts 27 (FIGS. 1and. 4). Castings 26a,26b are made of high-strength lightweight alloywith the metal distributed for maximum strength and minimum weight.. Thetwo castings 26a,26b support upper and lower pairs of transverse rollers30a,30b and "31a,31b best shown in-FIG. 2. Upperrollers 30a,30bfunctionprimarily as retainer rollers whereas the larger heavier duty rollers3la,3lb carry the principal weight of the conductor 32. In additionthere are two pairs of vertically disposed rollers journalled in theopposite ends of main frame 26, best shown in FIG. 1, namely, rollers33a,33b and the relatively larger and heavier-duty rollers 34a,34b. Thedescribed four pairs of rollers cooperate in forming a stringing tunnelthrough which conductor 32 extends while being pulled into its installedposition along the power line. As is made clear by FIGS. 2 through 5,conductor 32 is supported above and in general alignment with seatingchannel 17 of clamping unit 16 and is maintained in this elevatedposition until pulled into its fully installed position and properlytensioned.

Thereafter it is released and allowed to gravitate into seating channel17 in a manner to be described presently. As is made clear by FIGS. 4and 5, all rollers preferably include anti-friction bearing supportscarried by shafts mounted in frame members 26a,26b.

. 4 Referring to FIG. 4, it is pointedout that the heavy duty rollers34a are mounted on shafts 36secured to frame-26a by set screw 37. Thereduced lower end portion 38 of each shaft projects downwardly beyondthe adjacent portion of frame 260 and is sized and positioned to seat inone of theopenings 19 formed in a lug 18 projecting from one lateralside wallof the conductor clamping unit 16.

- ductor out of the seating channel 17 along curves .in the I Certain ofthese shafts are of special construction as will now be described;

Referring now to FIG. 5 itwill recognized that the lower transverse pairof rollers 3 1a,31b are mounted on shafts 40 having one end 'pivotaliysecured to main frame member 26b by a pivot pin 41. Rollers 31a are heldin position on shaft 40 by split ring keepers 43,43 seating in retainergrooves 44. The .left, hand end of shaft 40, viewed in FIG. 5, isflattened at 46 to provide an engaging surface for latch 47 carried byan operating lever 48 pivoted to main frame 26a by pin 50. Latch lever48 is normally biased to latching position by means including a pin 51loosely and slidably supported in the bore 52 of a tubular shaft 53supporting the upper transverse rollers 30a,30b. Pin 51 is urgedoutwardly against latch lever 48 by compression spring 54.

It is pointed out that the opposite ends of shaft 40 supporting thelower transverse rollers 31,3lb project into downwardly opening U-shapedchannels 56, 57 respectively, permitting the shaft to swing through aarc in a vertical plane. The normal conductor supporting position of therollers 31a is shown in fulllines in FIG. 5, whereas the releaseposition of these rollers in which the conductor is allowed to drop intoseating channel 17 is indicatedby the dot-and-dash lines in this sameFigure.

Referring to FIGS. 3 and6, it is pointed out that the conductorseatingunit 16 is provided with a threaded bore 60 for a cap screw 61. This capscrew extends downwardly through a flaring. bore, 62 formed in theconductor clamping jaw 63. This jaw includes a pair of lugs 64positioned to either side of cap screw 61 and adapted to extenddownwardly into a pair of notches 65,65 (FIG-1) openinglaterallyoutwardly from one sidewall of conductor seating unit 16. When thestringing block is mounted on the channel seating unit, clamping jaw 63is detached, inverted-and held captive on the upper edge of frame member26b inthe manner illustrated in FIGS. 1 and 2. For this purpose theupper edge of the frame is provided with a threaded bore 67 to receivecap screw 61. In this manner, the clamping jaw 63 is held captive in thevicinity of the insulator and its seating unit 16. After the conductorhas been strung OPERATION The mode of utilizing the described stringingblock assembly will be .quite evident from the foregoing detaileddescription of its components and their relationship to one another.Before installing stringing block assembly 10 on seating unit 16,clamping jaw 63 is removed and mounted along the top edge of thestringing block in the manner described above and illustrated in FIGS. 1and 2. The assembly of the stringing block to seating unit l6.is thenaccomplished merely by lowering assembly over the seating unit withlocator pins 38 (FIG. 4) aligned with a respective one of openings 19 inlugs 18. As this operation is performed the cammed nose 70 of latch21,22 cams over the similarly shaped upright edge of detent lug (FIG. 2)until'latch 21 seats beneath lug 20 under the urging of torsion spring72 (FIG. 2). This spring is quite stiff and firmly holds latch 21,22engaged beneath lug 20 thereby locking the stringing assembly 10 toseating unit 16.

If the particular insulator on which the stringing assembly is to bemounted is located at a curve in the power line, then it is desirableand important that the heavy duty vertical pair of rollers 34a,34b belocated on the inside of the curve as shown in FIG. 1. This isaccomplished by making certain that lugs 18 on conductor seating unit 16project from the inner side of the curve. To permit this, seating unit16 is designed for support in the insulator mounting bracket 12 with itslugs 18 facing in either lateral direction, and accomplished by rotatingunit 16 through 180 in a horizontal plane, if necessary, for lugs 18 toface in the desired direction. Stringing block assembly 10 is thensimilarly rotated, if necessary, to have locator pins 38 positioned toseat in openings 19 of lugs 18.

The hauling line for the conductor to be installed is attached to theadvance end of conductor 32 and passed in succession through thestringing tunnels of stringing blocks 10 mounted on each insulator alongthe power line. The lead end of this line is attached to suitable winchequipment and used to haul the line and the attached conductor intoplace. Throughout this operation both the haul line and the conductoritself is supported on the lower transverse pair of rollers 3la,3lb withsome lateral support being provided by upright pairs of rollers 33a,33b34a,34b. Along straight sections of thepower line these rollers carry noparticular load. However, along curved portions of the line, rollers34a,34b are under very considerable stress and for this reason are ofsubstantially heavier construction and are so positioned as to supportthe conductor in proper position for transfer into seating channel 17 atthe end of the stringing operation. The manner in which this isaccomplished is best illustrated in FIG. 1.

Lowering the strung and properly tensioned cable into the seatingchannel is accomplished readily and without tools by an operatorclimbing the pole and releasing latches 48,48. Desirably this is done insuccession allowing the associated one of the lower rollers 31a,31b topivot downwardly about pins 41 and allowing the conductor to gravitateinto channel 17. This operation opens the lower side of the stringingtunnel through assembly 10 thereby permitting the assembly to bedetached from the conductor clamping unit 16 merely by lifting itupwardly while holding latch lever 22 pivoted to its unlatched position.Clamping jaw 63 is then removed from its captive position on assembly10, inverted and secured in place over the conductor. The stringingassembly is now lowered to the ground and is available for furtherstringing operations.

While the particular conductor clamp with means for anchoring aconductor. stringing assembly thereto herein shown and disclosed indetail is fully capable of merely illustrative of the presentlypreferred embodiments of the invention and that no limitations areintended to the detail of construction or design herein shown other thanas defined in the appended claims.

I claim:

1. A conductor clamping unit adapted to be mounted on the outer end of arigidly supported power line insulator, said clamping unit having anelongated horizontally-disposed main body formed lengthwise thereof withan upwardly opening conductor seating channel having a depthsubstantially greater than the radius of the conductor to be clampedtherein, boss means projecting laterally from the opposite sides of themidportion of said main body having aligned wells in the outer endsthereof for pivotally securing said main body to the outer end of aninsulator with said conductor seating channel facing upwardly andunobstructed to receive and seat a conductor in said channel, meanscarried by said main body outwardly of said conductor seating channelarranged to cooperate with juxtaposed portions of a conductor stringingunit to hold the latter firmly assembled there to with said conductorseating channel parallel to and positioned to receive a conductor fromsaid stringing unit, conductor clamping jaw means extending across themid portion of said conductor seating channel rigidly clampablethereacross by fastener means located adjacent the mid portion of saidmain body and functioning independently of stringing unit holdingmeans.-

2. A conductor clamping unit as defined in claim 1 characterized in thatsaid clamping jaw means is of inverted J-shape having a stem portionslotted upwardly from the lower end thereof and sized to straddle saidboss means, and said fastener means comprising a cap screw seated in athreaded bore formed in said boss means.

3. A conductor clamping unit for power line conductors and designed toserve as a support for a conductor stringing block prior to use to clampa conductor therein, said clamping unit having an elongated main body ofgenerally U-shape in cross section to provide a deep conductor seatingchannel therealong and opening through the opposite ends thereof, saidchannel being substantially deeper throughout its length than the radiusof the conductor to be seated therein to safeguard against the escape ofa conductor being installed therein along curved sections of a powerline, said channel opening upwardly and having lug means projecting fromthe lateral sides thereof sized and shaped to seat an accurately locatedconductor stringing block means above said main body and in position torelease a strung conductor by gravity into said conductor seatingchannel, aligned boss means projecting laterally beyond the loweropposite sides of the mid portion of said main body having aligned wellsin their outer ends adapted to seat trunnion supports of a conductorclamp support bracket embracing and confined to the underside of saidclamping unit thereby leaving the area overlying the clamping unitunobstructed while stringing a conductor along the upper side of saidseating channel, and clamping jaw means attached to said main body andadapted to be secured in place crosswise of the mid length of the upperportion of said conductor seating channel and including fastener meanstherefor securable to said main body independently of said lug means.

l060l l 0207 5.;A conductor clamping unit as defined in clairn 3characterized in that said-clamping jaw' means includes a pair of lugsextending downwardly and straddling one of said boss means used topivotally support said clamping unit.

I I I III

1. A conductor clamping unit adapted to be mounted on the outer end of arigidly supported power line insulator, said clamping unit having anelongated horizontally-disposed main body formed lengthwise thereof withan upwardly opening conductor seating channel having a depthsubstantially greater than the radius of the conductor to be clampedtherein, boss means projecting laterally from the opposite sides of themidportion of said main body having aligned wells in the outer endsthereof for pivotally securing said main body to the outer end of aninsulator with said conductor seating channel facing upwardly andunobstructed to receive and seat a conductor in said channel, meanscarried by said main body outwardly of said conductor seating channelarranged to cooperate with juxtaposed portions of a conductor stringingunit to hold the latter firmly assembled there to with said conductorseating channel parallel to and positioned to receive a conductor fromsaid stringing unit, conductor clamping jaw means extending across themid portion of said conductor seating channel rigidly clampablethereacross by fastener means located adjacent the mid portion of saidmain body and functioning independently of stringing unit holding means.2. A conductor clamping unit as defined in claim 1 characterized in thatsaid clamping jaw means is of inverted J-shape having a stem portionslotted upwardly from the lower end thereof and sized to straddle saidboss means, and said fastener means comprising a cap screw seated in athreaded bore formed in said boss means.
 3. A conductor clamping unitfor power line conductors and designed to serve as a support for aconductor stringing block prior to use to clamp a conductor therein,said clamping unit having an elongated main body of generally U-shape incross section to provide a deep conductor seating channel therealong andopening tHrough the opposite ends thereof, said channel beingsubstantially deeper throughout its length than the radius of theconductor to be seated therein to safeguard against the escape of aconductor being installed therein along curved sections of a power line,said channel opening upwardly and having lug means projecting from thelateral sides thereof sized and shaped to seat an accurately locatedconductor stringing block means above said main body and in position torelease a strung conductor by gravity into said conductor seatingchannel, aligned boss means projecting laterally beyond the loweropposite sides of the mid portion of said main body having aligned wellsin their outer ends adapted to seat trunnion supports of a conductorclamp support bracket embracing and confined to the underside of saidclamping unit thereby leaving the area overlying the clamping unitunobstructed while stringing a conductor along the upper side of saidseating channel, and clamping jaw means attached to said main body andadapted to be secured in place crosswise of the mid length of the upperportion of said conductor seating channel and including fastener meanstherefor securable to said main body independently of said lug means. 4.A conductor clamping unit as defined in claim 3 characterized in that atleast one of said aligned boss means includes latch detent means adaptedto interlock with assembly latch means of a conductor stringing blockunit to hold the latter detachably in place on said main body while aconductor is being strung.
 5. A conductor clamping unit as defined inclaim 3 characterized in that said clamping jaw means includes a pair oflugs extending downwardly and straddling one of said boss means used topivotally support said clamping unit.